Class StackableWeapon

Stackable Weapon class A generic Weapon that can have a number of
weapons binded per instance It deals the number of weapons times weapon's
default damage This is used for cannons, reducing the number of instances
and bullets fired

on_impact(cls,
session,
weapon_id,
damage,
position)
Classmethod that deals damage to units at position, depending on
weapon_id Damage is done independent of the weapon instance, which
may not exist at the time damage is done